One thing I keep in mind while watching Sous Vide Everything videos is that they are very subjective and keep a very consistent rotation of people tasting their food. They also tend to only test things once, which (IMO) makes it hard to see their videos and know that their conclusions can be taken as a consistent result. As for butter when searing, go for it! Brown butter works well too as do other oils like canola oil, ghee, or clarified butter--really any oil with a decently high smoke point.
– moberemkFeb 28 at 19:32